sounds good. i just (like the day before yesterday-today) switched over my tanks, and im sure you know how nasty a tank looks after you do that. well i shoved AC in like everyorifice of my tank, (i put 2 in the filter, stuck one folded up in the place where my remora skimmer spits out water, rubberbanded over powerheads, and you know what? its crystal clear. like its been that way for years. i actually ADDED fish today! its crazy, like you know how you usually get amonia spikes after switching a tank? nothing. its incredible. the kind i use is HBH aqua-pure cut to fit filter pad Carbom for fresh& marine aquariums. it remover free floating waste and debris and toxins, and helps purify water (says the package.) and it cost me $8.99 for a 10" x 18" pad.